Personally, if funds were limitless I'd like a double neck with necks 120 degrees apart, one neck with some bass strings and low guitar strings, one with guitar strings. But am I worth it? Am I ****!

Here's another idea:

A guitar with all wound strings and some kind of built in device which doubles the pitch of the output from the higher 3 strings. This way all strings would have the same output making it possible to play tapping runs from low to high strings without loosing volume.
Perhaps it might be better to use all unwounds and halve the pitch of the lower 3. Either way some truss-rod adjustment would be required.

More naturally and economically:

A floydd rose fitted, through neck, 24 fret 7 string with an active humbucker pickup in the bridge with a coil tap and a little on off switch fitted next to the top E string. Mother of Pearl inlays, Gold hardware, Blue Sunburst. Classic sharpened Fender (Ibanez) shape but with a pointy headstock. Stop me drooling!